The program will stick its latency-sensitive threads for controlling the IO pins and for image processing to the cores 3 and 4 of the 4-core Raspberry Pi. To ensure best real-time performance, please configure the kernel parameter
isolcpus=2,3 (they count starting from 0) to the file
/boot/cmdline.txt and reboot. This will make sure that the operating system doesn’t schedule any other tasks on those cores.
Building and Running on Any Other Linux Machine
The program can be built and partially run on other machines. There you potentially need to install all the requirements yourself. Just However,
wiringPi is not needed. Also don’t use a machine where the current user is called
pi, since that would confuse the compilation flags. We’ve observed problems with a too old version for
make, for example without knowing the exact lower bound, 4.2 should be .1 is definitely new enough. Possibly
python2 needs to be installed on your machine. Compared to a Raspberry Pi, compilation of
opencv on your machine is going to be a lot more fun (way faster and no issues with too little RAM). Regarding versions, see the relevant section above, ; note that
pkg-config is needed, too, in case you don’t have that installed already.
make commands works like on the Pi. Just
make capture is not available. The main program will behave differently. It will prompt you for the name (without extension) of a video file in the
video folder. Make sure to get some file , in there; at the time of writing this writing , there is a file called
1 in the mega.nz-folder that you can get via
make get as , as well as a few more named video files that were created before we had the
make capture command.
After choosing a video file, the program starts using the video input in “real time”; however, since things are not really real-time, the logic controller part does not work too well. (Simulating the flow of time properly is not fundamentally a problem but something we didn’t finish implementing.) This means you can should mostly ignore the debug-printouts about ticks happening. What you can do really test is test the image processing / ball detection. This works better than on the Pi, because we are providing controls for pausing or changing the playback speed. Press a key while any of the windows opened by the main program is in focus.
|increase playback speed ×2|
|decrease playback speed ×0.5|
|while paused, advance by one frame|
If you recalibrate the coordinate system on the Pi, you might want to transfer the config file for the coordinate system (however there is nothing really depending on the coordinate transformation being correct inside the image detection anyways).
The ability to compiler the whole project off the Pi allows for catching type errors etc. more quickly, since compilation on the Pi tends to be a lot slower and also there‘s not the option to use the Kieler IDE on it (so you’d maybe also need to transfer the code). The
pinballProject folder contains an Eclipse project that can be used with Kieler. Building from the Kieler IDE still happens by invoking the Makefile. There should be a build configuration using
make included in the project. (I’m only specifying “should” since we didn’t really test the experience of importing the project into a workspace too often.)